My office building has parking on three elevations and grass at the front elevation. The front elevation develops efflorescence beginning every spring and continuing through the summer. The grass in this area is sprinkled. Could water from the soil be wicked up through the concrete foundation and into the brick, carrying minerals from the soil and depositing them on the walls? If not, what is causing the efflorescence?
The efflorescence is likely caused by water from the sprinkler saturating the walls. The white efflorescence is due to soluble compounds leached out of the mortar or the brick. If flashing was installed at the base of the wall, it should prevent water from wicking up the concrete. Position sprinklers so that water does not reach the walls. If this does not solve the problem, you may need to examine the base flashings to see if they are installed properly.